Method and apparatus for the manufacture of metal tubes



METHOD AND APPARATUS FOR THE MANUFACTURE OF METAL TUBES.

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I FZI.3 A WA? Mar.- 6, 1923. 1,447,821. E. SCHNEIDER. METHOD AND APPARATUS FOR THE MANUFACTURE OF METAL TUBES.

FILED JULY26| I92]. 3 SHEETSSHEET 2- D Wfl%///////// H fi wuu A D L K I i nnnunnn Manfi, 1923.

E. SCHNEIDEB.

METHOD AND APPARATUS FOR THE MANUFACTURE OF METAL TUBES.

' FILED JULYZS, I921.

s SHEETS-LSHEET a.

Patented Mar. 6, 1923.

FEED STATES Parana" & or PARIS,

FRANCE, A LIMITED JOINT-STOCK COMPANY OF FRANCE.

METHOD AND APPARATUS FOR THE MANUFACTURE OF METAL TUBES.

Application filed July 26, 1921. Serial No. 487,682.

To all whom it may concern:

Be itknown that I, EUGENE SCHNEIDER, a citizen of the Republic of France, residing at 42 Rue dAnjou, Paris, France, have invented new and useful Improvements in Method and Apparatus for the Manufacture of Metal Tubes, which is fully set forth in the following specification.

This invention has for its object to provide an improved apparatus for the manufacture of very strong metal tubes by the compressive action of a liquid under pressure. The usual process of manlifacturing metal tubes by the compressive action of a liquid under pressure consists in causing a metal tube previously made with an internal diameter smaller than the desired internal diameter of the finished tube, to assume the said 'desiredinternal diameter by compression of the inner layers ofthe metal which are thus gripped tightly by the outer layers that are under tensile strain. a

That known process is generally performed by forcing the liquid under pressure into the annular space comprised between "the inner surface of the tube to be manufactured and the outer surface of a very strong bar or mandrel.

That process has the drawback that it is necessary to provide perfectly tight joints at the ends of the mandrel. More especially in manufacturing tubes of great thickness and very great length, such as tubes for the manufacture of long-range guns, it is neceswhich it is desired to obtain, so as to be able said greater length. The compressed tube.

sary to subject the tube to different pressures gradually diminishing from the breech to the muzzle of the gun, and for this purpose it is necessary to produce the compression efi'ect in successive zones by correspondingly to accommodate the end joints within the must then be cut to the said desired length.

The improved apparatus of this invention not only obviates the last mentioned draw backs, but it also allows of effecting the compression of the tube without the use of any tight joint.

Kccording to this invention the liquid un der pressure is admitted into a pocket madeof sheet metal, brass, rubber or other de formablematerial; the external longitudinal surface of the pocket being in contact with the lnternal surface of the tube to be compressed, at the commencement of the operatlon. Thls closed pocket is provided at one end only with a duct for the admission of the liquld, and with a duct for the escape of air or the liquid. The pocket is deformed together with the tube to be compressed and thus transmlts the pressure to the latter.

Some examples of the application of this inventlon to the compression of a gun barrel tube are illustrated in the accompanying drawings in which Figs. 1 and 1 comprise an axial sectional elevation of the tube to be compressed. F I*1gl. 2 is a section on the line 22 of 1g. g Figs. 3,3 and 4,46 are longitudinal sectlonal elevations similar to Fig. 1, showing the successive applications of hollow sleeves of gradually decreased lengths for use in the compression by means of increasing pressures acting upon successive zones of the length of the tube to be manufactured.

F ig. 5 is a sectional elevation of a modification.

In Figs. 1 to 4, A is the tube to be compressed between the transverse vertical plane a near the breech and the muzzle a A very strong compression mandrel B is held at one end in an annular plug C screwed into the end of the tube that is intended to form the breech of the gun. This mandrel projects at its other end beyond the muzzle a of the gun tube. 1 a

A pocket D having the form of a hollow sleeve, made of thin sheet metal, brass, rubber or other suitable material, is placed between the mandrel B and the inner surface A of the tube to be manufactured.

The pocketsleeve D is entirely closed at its forward end. To its rearward end there are suitably connected by welding or other- W186 two pipes E, F serving respectively for the admission ofthe liquid under pressure, and for the escape of air .or excess liquid, or for the exit of the liquid for emptying the pocket-sleeve. The front end portion of the pocket sleeve D projects beyond the muzzle end a of the-tube, and bears with its outer-surface against a strong sleeve G. whereas its end face bears through the mediumof a splitting I against a nut H. 7 V The sleeve G is held up against the muzzle a? of the tube by a divided collar J-- J whose sections are fastened together by bolts J The thin deformable pocket-sleeve D has no joints whatever; by reason of its extension beyond the muzzle (2. it allows of applying the pressure-over the entire length c -a m Since it (the pocket-sleeve D) is perfectly tight, there is no risk of any leakage occurring during the compressingoperation. When it is desired to apply increased pressures to different zones of the tube, use is made of a pocket-sleeve D extending the whole length of the tube as shown in Fig. 1, and the tube is subjected to a uniform pressure through its Whole length. Then the mandrel B and the pocket sleeve D are withdrawn, and the latter is replaced by a pock'etsleeve D? of reduced length (Fig.

v3), the space thus left between the front end (Z of thisshorter pocket-sleeve and the nut H beingfilled up by a distance piece K. Liquid under a pressure higher than that which was employed in thepocket-sleeve D, is now admitted into the pocket sleeve D The mandrel B and the pocket-sleeve D are withdrawn afresh, and the latter is replaced by a still shorter pocket-sleeve D (Fig. l) likewise thedistancepiece K is replaced at the same time by a longer distance piece K which fills up the entire annular space left between the front end 03 of the pocketjsleeve D? and the nut H. A split ring L may be interposed between the front ends of the ocket sleeve D D and the distance pieces K The split ring I may be em ployed for this purpose. I

W-ith the vapparatus shown in Fig. 5, it is possible by means of a single continuous pocket-sleeve to effect the compression of a gun tube by applying different deformzones I,,.II, III diminishing in thickness fing pressures to diflterentzones of the length of the said tube. In this example the mandrel is entirely dispensed with, and a uniform internal pressure is exerted within a deformable tubular pocket-sleeve having walls of different thicknesses.

In the illustrated example it isassumed that the tube to be treated comprises three H from the breech to the muzzle,

The deformable pocket-sleeve whose external surface p bears against the internal surface of the tube to be treated has walls 6 e 6 of increasing thicknesses for lengths 1 corresponding to the zones I, II and III.

If a suitable pressure is applied to the inside of the pocket-sleeve, after havingsuitably chosen the thicknesses e e a it will be perceived that by' neans of this pressure (which isunifo'r m throughout the entire ength of) the pocketssleeve) suitably ;dimi h nerressne ay be merited p the zones 1?, II, IIIof the tube.

a liquid under pressure comprising, in combination, an elastic pocket having a plurality of openings in one end thereof, means positioned atthe opposite end of said pocket, and means engaging the tube to be manufactured for rigidly holding said first named means in contact with said pocket.

2. vAn apparatus for the manufacture of metal tubes by the compressive action of a liquid under pressure comprising in combination, an elastic pocket, a pipe at one end of said tube for the admission of liquid under pressure, a discharge pipe having communication with said pocket through said end, said pocket being of such length that the opposite end thereof projects beyond the forward end of the tube to be manufactured, and means rigidly supporting' said projecting pocket end.

8. An apparatus forthe manufacture of metal tubes by the compressive action of a liquid under pressure comprising in combination, a cylindricalpocket, apipe at one end of said tube for the admission of liquid under pressure, a discharge pipe having communication with said pocket through said end, said pocket being of such length that. the opposite end thereof projects beyond the forward end of the tubet'o be manufactured, and means ri idly supporting said projecting pocket en v 4. The method ofmanu'facturing a metal tube of great strength which comprises inserting, and rigidly supporting a mandrel in said tube, said mandrel being of greater length than the tube and projecting from "the forward end thereof,,inserting an elastic pocket between said mandrel and the inner surface of said tube, r gidly supporting the 7 forward ends of said mandrel and pocket, and introducing a liquid under pressure into said pocket through'the opposite end thereof 1 5. Means for manufacturing metal tubes by the compressive action of a liquid pres sure comprising in combination, a mandrel rigidly supported in said tube, an elastic pocket having a' plurality of openings in one end thereof adaptedto be positioned between said mandrel and said tube, and means rigidly supporting the forward end of said pocket, said last named means comprising a split ring, a member abutting said ring, and a sleeve surrounding "said member.

6. The method of manufacturing a metal tube by the compressive actionofa fluid applied at increased pressures to difierent Zones of the tube which eempriies insert: ing and rigidly su portin ii'l'said tube Bil elastic pocket, introducing a liquid under pressure into said pocket, removing said pressure and withdrawing said pocket, and successively inserting and rigidly supporting 5 in the tube elasticpocliets of different reduced lengths, and introducing a liquid under difierent pressures into said pockets.

EUGENE SCHNEIDER.

Witnesses ANDRE MOSTIGKER, LOUIS GARDET. 

